Merge pull request #316 from depot/feat/gocache-prefer-depot-cache-token

feat: default gocache token to DEPOT_CACHE_TOKEN

Merge pull request #315 from depot/refactor/move-depot-gocache

refactor: write GOCACHEPROG cache into GOCACHE

Merge pull request #314 from depot/docs/update-gocacheprog

docs: update gocacheprog docs

Merge pull request #312 from depot/retry-container-pull

Retry bootstrapping failures

Merge pull request #309 from depot/fix-default-path

Merge pull request #308 from depot/save-existing-build

Merge pull request #306 from depot/ecr-public

Merge pull request #304 from depot/retry-push-on-error

Retry `depot push` on 5xx errors

Merge pull request #303 from depot/docker-config

Allow specifying `DOCKER_CONFIG` via `--config`

Merge pull request #302 from depot/fix-gha-cache